Beyond the rim of nowhere, the Sierra
de San Borja (right) marches to the
horizon. Few humans inhabit the range's
mesas and steep canyons, home to the
cougar, the mountain sheep, and the deer.
Nineteenth-century prospectors searched
the nearly waterless hills in vain for gold
and silver. The cinder cones of two vol
canoes that flamed less than 5,000 years
ago crown this view.
Surf dimples the sand, but no foot
prints scar an unsullied Pacific beach
(left) west of Cabo San Lucas.
Only tidal waters from the Gulf of
California wash the mud flats of the
Colorado River delta (below). Born bold
and fresh in the Rocky Mountains, the
southward-flowing stream loses its sweet
ness as water siphoned off for irrigation
picks up salt from the soil and then re
turns to the river. Irrigation projects in
seven states and in Mexico's Mexicali
Valley diminish the Colorado's flow until
it disappears into the sand a few miles
from its former mouth.
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